Cleaner silencer assembly



- Dec. 2, 1958 Filed Oct. 4, 1955 2 Sheets-Sheet 1 X9 2 d9 3 :w

INVENTOR.

ATTORNEY Dec. 2, 1958 N. J. AMLOTT 2,862,572

CLEANER SILENCER ASSEMBLY Filed 001:. 4, 1955 2 Sheets-Sheet 2 INVENTOR.

g /Emmy cfQw/Zff ATTORNEY United States Patent P CLEANER SILENCER ASSEMBLY Norman J. Amlott, Grand Blanc, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporatiou of Delaware Application October 4, 1955, Serial N 0. 538,502

2 Claims. (Cl. 183-44) This invention relates to cleaner silencer assemblies for engines and has particular relation to cleaner silencer assemblies especially applicable for use with extrapowered, high speed, high compression ratio, internal combustion engines for automotive and other uses.

A practice has developed recently of increasing the horse power of engines by making changes principally involving the induction and the exhaust systems of the engines. Multiple induction systems have been proposed, each having separate carburetors, and these generally are compound carburetors in which primary and secondary fuel supply passages are provided. More recently it has been proposed to provide such engines with a plurality of four-barrel carburetors. These are usually constructed to provide two primary passages and two secondary passages each. In an engine having two or more four-barrel carburetors of this kind it will be apparent that difficulties may be encountered in cleaning the air employed in such induction systems and in silencing the noises which these induction systems produce.

This invention has resulted from an effort to construct a cleaner silencer unit that can be located in the greatly reduced space available in vehicles employing such engines and which, nevertheless, will supply the clean air required and will attenuate the sounds resulting from the induction systems thereof.

It is proposed to provide an elongated casing which will extend transversely across an engine and above the induction system thereof. The middle of this casing may be connected to the various induction system inlets or carburetors which usually extend lengthwise of the engine for supplying the fuel and air required. It is also proposed to connect air cleaners to the casing and to locate such air cleaners on each side of the engine and on opposite sides of the carburetors or other means for supplying fuel and air for operating the engine. Such an arrangement may be employed to supply clean air for operating the engine but the space available was found not to be suflicient for the construction of resonating chambers or other means usually employed in the attenuation of sounds resulting from operation of the induction system of the engine. It was discovered, however, that the structure that could be located in the space available could be made to satisfactorily attenuate the induction system noises and sounds by constructing something similar to a low pass filter sound attenuating system. It was found that by constructing expansion chambers and acoustical impedance means within the structure it was possible to attenuate the induction system sounds. Such acoustical impedance means may embrace acoustical capacitance chambers in the cleaner units and the casing inlets, these being connected to the expansion chamber formed by the interior of the casing by acoustical inertance conduits of suitable form.

In the drawings:

Fig. 1 is a fragmentary end elevational view of the upper part of an internal combustion engine having a Patented Dec. 2, 1958 cleaner silencer assembly associated with the induction system thereof,

Fig. 2 is a fragmentary view of one end of the cleaner silencer assembly and having parts thereof broken away to better illustrate the interior construction thereof, and

Fig. 3 is a fragmentary plan view of the engine illustrated by Fig. 1 and particularly illustrating the silencer unit casing embodying the invention. 'The silencer unit casing has parts thereof broken away and shown in cross section to better illustrate the interior construction there- The engine 10, which is partly shown by Figs, 1 and 3, in the present instance is a V-type eight cylinder internal combustion engine for automotive and other uses. The engine embodies an engine block 11, engine heads 12, and an induction system 13 supported by the heads 12 and disposed above the block. In the present instance the induction system consists of an inlet manifold 14 embodying various passages leading to the cylinders of the engine. The manifold may be supplied with combustible mixture by a pair of four-barrel compound carburetors indicated at 16 and 17. Each of the carburetors 16 and 17 may include a pair of primary passages and a pair of secondary passages all leading to the various passages in the manifold 13 for supplying the cylinders of the engine. The inlets to the carburetors 16 and 17 provide induction system inlets indicated at 18 and 19 and adapted to supply air for operating the engine 10.

An elongated casing 21 is adapted to be secured across the upper part of the engine 10 by wing nuts 22 attached casing 21 and the cleaners 24 provides an efiicient utilization of the limited space available when an engine such as the engine 10 is employed for automotive and other similar purposes.

The air cleaners 23 and 24 comprise outer casings 26 and inner casing 27 adapted to be secured together and to the opposite ends of the casing 21 by bolts 28 and wing nuts 29. The inner casings 27 are spaced from and extend outwardly from the upper part of the outer casings 26 to provide air inlets 31 which lead to annular chambers in the inner casings 27 adapted to contain an-" nular filter elements 32. In the present instance, the outer casings have inwardly projecting cylindrical walls 33 which extend inwardly within inner walls 34 of the inner casings 27 and around which the filter elements 32 are disposed. The walls 33 provide chambers 36 forming parts of outlet chambers 37 which extend across the inner casings 27 above the filter elements 32. The inner casings 27 have covers 38 which extend across the outlet chambers 37 and which, in turn, are formed to provide outlets 39 that are received in openings formed in the lower Wall 41 of the casing 21 and adjacent the opposite ends thereof. The outlets 39 are adapted to be connected to collars 42 which extend between the lower wall 41 and the upper wall 43 of the casing 21 and adjacent the ends thereof. The collars 42 may have any number of outlets for air, in the present instance there being two of such outlets connected to nipples 44 projecting from the sides thereof. The nipples are adapted to receive tubes 46 and 47, the tube 46 leading from each casing being in the present instance projected toward the induction system inlet 18, and the tubes 47 toward the induction system inlet 19.

For convenience in manufacturing, the casing 21 may be made in upper and lower sections 49 and 51 respectively, and the collars 42 likewise may be made in upper and lower sections 52 and 53 respectively.

It will be apparent that the air supplied to each of the cleaners 23 and 24 passes through cleaner inlets 31, filter chambers 32, cleaner outlet chambers 37, cleaner outlets 39, the chambers 56 Within the collars 42, the passages 58 through the tubes or conduits 44, the chamber 54 within the interior of the casing 21 and the induction system inlets 18 and 19.

The cleaner outlets 39 are combination air inlets and acoustical outlets for the chamber 54 within the casing 21. The openings in the casing 21 by which the chamber 54 is connected to the inlets 18 and 19 are combination air outlets and acoustical inlets for the casing 21. The inlets 18 and 1-9 are combination air inlets and acoustical .outlets for the induction system 13 of the engine 159.

The sounds emanating from the induction system of the engine will be received within the chamber 54 in the casing 21 which provides an expansion'chamber' for the sound. In the expansion chamber '54 the sounds travel in all directions and will engage and Vibrate the walls of the casing, resulting in an interference of sound waves which will tend to attenuate some of the sounds. Passages 58 in tubes 46 and 47 will serve as acoustical inertances which will conduct only certain wave lengths of sound to the chambers 56. The chambers 56 and the spaces forming the cleaner outlet chambers 37 will pro vide acoustical capacitant chambers which will serve as impedence means opposing the passage of sound waves through the cleaners 23 and 24. The filter element 32 also tends to absorb sound waves not previously attenuated and the inlet passages 31 and serves impede the emanation of sound from the cleaner inlets.

I claim:

1. A cleaner silencer assembly comprising, a casing having a plurality of combination air outlets and acoustical inlets adapted to be secured to the combination air inlets and acoustical outlets of an induction system for an internal combustion engine, a combination air inlet and acoustical outlet for said casing and having an air cleaner attached thereto for supplying cleaned air to said casing, said casing providing an acoustical expansion chamber receiving sounds transmitted from said induction system and conveying air from said casing air inlet to said casing air outlets, and a plurality of air inlet and acoustical inertance conduits connecting said casing air inlet and said casing, each of said conduits extending toward one of said casing air outlets and conveying air from said casing air inlet to said casing and aid casing air outlets, said conduits also being tuned to attenuate sounds emanating from said induction system of said engine and transmitted to said acoustical expansion chamber.

2. A cleaner silencer assembly as defined by claim 1 and in which said casing is an elongated casing adapted to extend across a V-type engine with said combination air outlets and acoustical inlets being formed in the middle and transversely of said casing, there being one of said combination casing air inlets and acoustical outlets at each end of said casing and on opposite sides of said engine, each of said combination air inlets and acoustical outlets being provided with one of said air cleaners and with a vplurality of said air inlet and acoustical inertance conduits so connecting said casing air inlet and said casing and so extending towards said casing air outlets, all of said conduits being tuned to attenuate sounds emanating from said induction system of said engine and transmitted to said acoustical expansion chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,521,400 Shaw Dec. 30, 1924 2,322,895 Steenson June 29, 1943 2,391,933 Wharam Jan. 1., 1946 2,553,326 Manning May 15, 1951 2,626,009 'Sebok Jan. 20, 1953 2,690,331 Weldy Sept. 28, 1954 2,748,891 Amlott June 5, 1956 FOREIGN PATENTS 465,365 Great Britain May 6, 1937 

